Re: [PATCH nft 5/5] datatype: check against negative "type" argument in datatype_lookup()

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Tue, Aug 29, 2023 at 09:10:26PM +0200, Pablo Neira Ayuso wrote:
> On Tue, Aug 29, 2023 at 08:54:11PM +0200, Thomas Haller wrote:
> > An enum can be either signed or unsigned (implementation defined).
> > 
> > datatype_lookup() checks for invalid type arguments. Also check, whether
> > the argument is not negative (which, depending on the compiler it may
> > never be).
> > 
> > Signed-off-by: Thomas Haller <thaller@redhat.com>
> > ---
> >  src/datatype.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/src/datatype.c b/src/datatype.c
> > index ba1192c83595..91735ff8b360 100644
> > --- a/src/datatype.c
> > +++ b/src/datatype.c
> > @@ -87,7 +87,7 @@ const struct datatype *datatype_lookup(enum datatypes type)
> >  {
> >  	BUILD_BUG_ON(TYPE_MAX & ~TYPE_MASK);
> >  
> > -	if (type > TYPE_MAX)
> > +	if ((uintmax_t) type > TYPE_MAX)
> 
>             uint32_t ?

Another question: What warning does clang print on this one?
Description does not specify.

> >  		return NULL;
> >  	return datatypes[type];
> >  }
> > -- 
> > 2.41.0
> >